ar 15 bolt wont stay open

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valmet762

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my ar 15 (dlask arms lower and colt upper) bolt will not stay open with an empty mag inserted.. it also doesn't stay open without a mag inserted and i hold down the bottom part of the bolt release.. sometimes it does catch but if i even give the rifle a dirty loook, the bolt slams shut..

it does this with lots of different mags... when i pull the bolt back, the bolt catch barely reaches the bolt.. if somebody with a micrometer can measure the amount of movement (up and down) in a working latch it would be appreciated..

my mags do push up the latch but not far enough to catch enough of the bolt, even though the latch is pushed to the upper limit of travel..

there is no play between the upper and lower receiver and the fit is nice and tight, so i dont think it has anything to do with that..

i googled this problem and found some info, but none of it seems to relate to my problem..

i'll try to post some photos soon.. in the meantime, any help from you pros out there would be appreciated.
 
Mine goes from about 7/32" to 3/8", it nearly doubles in height.

Does it look right, or does it appear to be ground down?

There is a little plunger that goes in after the spring, perhaps a second one was accidently put in during assembly which would restrict movement?
 
valmet762 said:
my ar 15 (dlask arms lower and colt upper) bolt will not stay open with an empty mag inserted.. it also doesn't stay open without a mag inserted and i hold down the bottom part of the bolt release.. sometimes it does catch but if i even give the rifle a dirty loook, the bolt slams shut..

it does this with lots of different mags... when i pull the bolt back, the bolt catch barely reaches the bolt.. if somebody with a micrometer can measure the amount of movement (up and down) in a working latch it would be appreciated..

my mags do push up the latch but not far enough to catch enough of the bolt, even though the latch is pushed to the upper limit of travel..

there is no play between the upper and lower receiver and the fit is nice and tight, so i dont think it has anything to do with that..

i googled this problem and found some info, but none of it seems to relate to my problem..

i'll try to post some photos soon.. in the meantime, any help from you pros out there would be appreciated.
Click to expand...

1. Take magazine out of the gun and manually lock the bolt back using the bolt release. Hit the side of the butt stock sharply in an attempt to dislodge the bolt and have it go into battery. If it doesn't trip then it has to do with the magazine.
2. Try using a new or high quality magazine. Often insufficient magazine tension results in not enough tensioin being upplied upwards to hold the bolt stop in place.
3. If problem persists, try looking at the face of the stop. It may have been peened, rounded off, or defective, which would result in insufficient material or incorrect geometry of the part.

L
 
Do you maybe have a rifle buffer installed in a carbine retractable stock, or a rifle buffer spring instead of a shorter carbine spring?

Do you have an SP1 stock installed, but with the longer buttplate screw from an A2 stock?
 
Is it possible for you to take a picture of your lower (the area with the bolt release in particular) and post it?
 
thanks for the tips guys... cant seem to find any of the problems you guys described.. here's some pics.. sorry for the size..

DSC04413.jpg


DSC04417.jpg


DSC04419.jpg
 
If you remove the magazine, pull the bolt back and use a pencil (or some other long-ish object) to push the bolt catch up, will it sit any higher on the bolt face? Or is that as high as it goes?
On mine, the bolt catch will come as high as the chamfer on the bolt face.
When you pull the bolt all the way back, is there a gap between the bolt face and that catch? I have about 1/8" between the two faces.
With the upper off and no mag in, what's the highest that catch will go when engaged? At it's highest point, mine is .418" (just shy of 7/16") from the top of the receiver to the top of the catch.
Does the catch seem to move freely in it's slot or does it feel like it's binding? Sometime the slots are tight or have burrs that bind on them.
Being a big PITA here, but could you take one more pic from the side, on an angle? (so we can see the position of the pin/bolt catch).

My initial theories are:
A) The bolt catch is out of spec (I doubt it)
B) The slot of the left hand side where the spring is (or the hole that the spring sits in) are not deep enough to allow the catch to pivot any higher. (Doubt it)
C) There are burrs or the slots are tight enough that the catch is binding (More likely)
D) Wrong spring/incorrectly installed plunger (My guess)

Did you get it assembled from Dlask or did you assemble it yourself? The reason I ask is that the stock assembly looks like the ones that Questar sells (not saying that dlask doesn't have them either, thats entirely possible), which leads me to beleive that maybe if you assembled it, when the plunger was put in, maybe it was put in backward. Normally the small end goes inside the spring (ball end facing out), if you reverse it, you essentially 'lengthen' that pin and it won't go in far enough.
The only way to know is to remove the roll pin and see which way it's installed.
 
i measured the height of the latch at its highest.. its exactly .3" from the top of the receiver.. this is as far as it goes..

I bought the lower already assembled on the EE about 4 months ago.. it shoots fine other than the catch problem ... its had this problem from the day i bought it..

i'll check the spring and and plunger.
 
:rockOn:FIXED IT !!!!:rockOn:

Thanks to all you guys for your input...

I took off the bolt catch checked the spring and plunger.. looked ok..

i took my dremmel tool and ground the catch, "a red one" from the side that goes up against the plunger and reinstalled it..

the highest it sits now is .36" and catches every time with all my mags.. it also stays open without a mag installed..

it looks like the catch may have been "out of spec"..

"happiness is a totally operational AR"
 
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I see you have one of Dlask's very first receivers. They were powder coated. Did you look into the bolt catch plunger channel if there was any excess powder coating residue? This was a common occurrence then.

With mine, the buffer retainer channel had residue in it. I think there was residue in the bolt catch channel too. That would definitely impede the bolt catch to travel high enough.
 
easy said:
I see you have one of Dlask's very first receivers. They were powder coated. Did you look into the bolt catch plunger channel if there was any excess powder coating residue? This was a common occurrence then.

With mine, the buffer retainer channel had residue in it. I think there was residue in the bolt catch channel too. That would definitely impede the bolt catch to travel high enough.
Click to expand...

i checked for "stuff" in the plunger channel.. didn't find anything, or i should say nothing came out.. maybe something caked in there pretty solid, but i couldn't tell..

dremmel tool on the catch seems to have done the trick.. for now.
 
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